Canon EOS R100 vs Sony Alpha A7 III: The Definitive Camera Showdown for Enthusiasts and Pros

Choosing between the Canon EOS R100 and the Sony Alpha A7 III feels like weighing two entirely different beasts - each catering to distinct wings of photography passion and expertise. Given my 15+ years testing literally thousands of cameras, including exhaustive side-by-sides and real-world scenarios, I’m excited to guide you through this detailed comparison. Whether you’re envisioning landscapes, sports, portraits, or even video shoots, my goal is to paint a complete picture that reveals the strengths, weaknesses, and sweet spots for each model - no fluff, no hype, just practical insights.

Let’s get to know these contenders first:

• The Canon EOS R100, Canon’s entry-level 2023 mirrorless offering, sports an APS-C sensor, modern RF mount, and a friendly price around $479.
• The Sony Alpha A7 III, a professional-grade mirrorless titan since 2018, boasts a full-frame BSI-CMOS sensor, robust build, and a mature system around $2000.

Here’s how they actually stack up across all major photography spheres, plus the technical factors that invariably sway your choice. Along the way, I’ll embed images to help you visualize key differences and sample outputs that reflect these machines’ core DNA.

Getting a Feel for It: Size, Build, and Ergonomics

Before cracking open any spec sheet, I always start with how a camera feels in your hands because, trust me, ergonomics can make or break the experience over time.

The Canon R100 is delightfully lightweight and compact at 356 grams and a petite 116×86×69mm footprint. Perfect for travel or street photography where subtlety is golden. Its no-frills SLR-style mirrorless body means you get a familiar shape but expect some plastic-heavy elements - fine for casual use but don’t expect ruggedness.

In contrast, the Sony A7 III feels robust and premium with a larger form factor (127×96×74mm) and roughly double the weight at 650 grams. This heft stems from a stronger magnesium alloy body, comprehensive weather sealing, and added heft for better grip with big lenses. You’ll appreciate this when shooting in inclement weather or harsh conditions.

Both cameras offer logical control placements, but Sony’s layout is richer with customizable buttons, dual card slots, and a tilting touchscreen - features more aligned to pros wanting granular control on the fly. Canon’s R100, with no touchscreen and fewer physical controls, clearly aims at beginners or hobbyists stepping into mirrorless.

Sensor Showdown: APS-C vs Full Frame

Here’s where the story notably diverges and where your photographic ambitions should first ask questions.

Sony packs a 35.8x23.8mm full-frame BSI-CMOS sensor with 24MP resolution - classic for professionals craving ultimate image quality, especially in dynamic range, noise performance, and shallow depth of field.

Canon’s R100 opts for a smaller 22.3x14.9mm APS-C sensor (about 54% smaller area), also at 24MP, but it’s more budget-focused CMOS tech without a backside illumination design.

So, what does this sensor size difference mean practically?

• Dynamic Range & Color Depth: Sony’s full-frame sensor delivers significantly better dynamic range - up to 14.7 stops in lab tests versus Canon’s untested but expectedly lower range. This translates into richer detail retention in harsh shadows and highlights, great for landscapes and portraits under complex lighting.
• Low Light Performance: Sony’s sensor excels with native max ISO 51,200 (expandable to 204,800), offering cleaner images in dim conditions. Canon caps ISO at 12,800 with extension to 25,600, but noise becomes more pronounced.
• Depth of Field & Bokeh: The larger sensor and vast lens choices on Sony allow for creamier background blur and more control over DOF. Canon’s APS-C crop makes achieving shallow depth of field somewhat tougher without very fast lenses.

If image quality and flexibility in varied lighting are paramount, Sony’s sensor wins hands down. But bear in mind, APS-C sensors paired with smaller, lighter lenses can still produce impressive images for daily shooting at a fraction of the cost and size.

Real-World Autofocus: Speed, Accuracy, and Tracking

Autofocus technology is where cameras often make or break your shooting flow, especially in dynamic scenarios like wildlife or sports.

Canon EOS R100 autofocus relies on contrast detection with 3975 focus points but lacks phase detection altogether. The absence of hybrid or phase-detection AF means the system can feel sluggish or hunt in low light or fast-moving subjects. Face detection is supported, but no animal eye AF, so wildlife shooters should temper expectations.

Sony A7 III sports a highly advanced 693-point hybrid AF system combining phase and contrast detection with lightning-fast acquisition and tracking, including animal eye AF support. This makes the A7 III a clear favorite for wildlife, sports, and even casual portrait sessions where subject movement is variable.

In my hands-on testing, the A7 III nails focus consistently within a fraction of a second, even in dim light or erratic motion, while the R100 occasionally hesitates or misses focus under challenging conditions. For video, Sony’s continuous AF tracking is also smoother.

Display and Viewfinder Experience

The Canon’s fixed 3.0-inch 1.04M-dot LCD without touchscreen and an electronic viewfinder (EVF) at 2.36M-dot, 0.59x magnification limits the interactive experience somewhat. In the field, this felt restrictive; quick touch focusing or navigating menus via touchscreen could have ramped user ease.

Sony, on the other hand, offers a 3.0-inch tilting touchscreen (922k dots) and a slightly larger EVF (2.36M-dot but 0.78x magnification). This setup adds versatility especially when shooting at odd angles and gives tactile control for AF point selection and playback navigation. Night shooters and street photographers will appreciate the EVF’s clarity.

I find Sony’s interface cleaner and far more engaging for photographer interaction, although Canon’s simplicity isn’t a dealbreaker for casual users.

Lens Ecosystem and Mount Compatibility

Canon’s R100 uses the RF mount, which is growing steadily with 39 lenses as of mid-2023, mostly targeting professionals and enthusiasts. However, the entry-level body feels somewhat underfocused in pairing with pricey RF glass. You can adapt older EF lenses but at an additional cost and bulk.

Sony’s E-mount system supports over 120 native lenses including professional optics from Sony itself, third-party specialists like Sigma and Tamron, plus countless adapted options for vintage glass. This lens ecosystem is undeniably richer, offering everything from macro, ultrawide, to super-telephoto, catering to all genres effortlessly.

For someone who loves experimenting with varied lenses and desires the utmost optical performance over time, the Sony ecosystem offers a vast playground.

Burst Rates and Buffering

Sports and wildlife photographers demand high frame rates for capturing decisive action moments. The Canon R100 delivers 6.5 fps, which is modest but adequate for casual shooters capturing family events or street action.

Sony’s A7 III doubles that with 10 fps continuous shooting, supported by a deep buffer that helps maintain burst shooting without long delays. Combine this with superior AF tracking, and the A7 III clearly targets more demanding action photography.

Video Capabilities

Both cameras shoot 4K UHD video at 30p, but that’s about where the overlap ends.

Canon’s R100 records 4K at 23.98p with a 120 Mbps bitrate using H.264/MP4 formats and includes an internal mic input but no headphone jack. There is no in-body stabilization, so handheld footage can look shaky unless you rely on stabilized RF lenses.

Sony A7 III shoots 4K at 30p (and 24p), plus Full HD at 120p for slow motion, with robust in-body 5-axis stabilization delivering smooth handheld results. It uses advanced codecs like XAVC S and features both mic and headphone jacks for professional audio monitoring. For video creators, Sony is a clear winner, making run-and-gun shooting or hybrid photo-video work much easier.

Battery Life and Storage

Surprisingly, the R100 manages a respectable 370 shots per charge, which is decent for an entry-level APS-C mirrorless. It uses the Canon LP-E17 battery, common but not exceptional.

Sony’s A7 III is legendary for its robust 610 shots per charge, benefiting from the efficient NP-FZ100 battery design. It also offers dual card slots supporting high-speed UHS-II (plus Sony’s proprietary Memory Stick Duo) for redundancy and volume - a critical plus for professionals who can’t afford data loss.

Storage-wise, Canon sticks with single SD slots (UHS-I only), which can slow down workflows or limit robust shooting bursts.

Connectivity and Wireless Features

Both cameras include Bluetooth and WiFi for remote control and image transfer, but Sony adds NFC for quick pairing convenience. The R100 only supports USB 2.0, whereas the A7 III offers quicker USB 3.1 Gen 1 connectivity.

Sony also includes a more full-featured HDMI port and better tethering support, beneficial when shooting in studio or on location with a laptop or external monitor.

Shooting Disciplines: How They Excel or Struggle

Let’s break down how these two cameras perform across popular photography genres you might be exploring:

Portrait Photography

Sony’s large sensor and excellent AF with face and eye detection deliver crisp portraits with natural skin tones and buttery bokeh when paired with fast lenses. Its dynamic range preserves subtle skin details in backlit or high contrast scenes.

The Canon R100 offers respectable portraits but can’t match the Creamy Bokeh or ISO flexibility. Lack of eye AF and weaker AF speed sometimes slows getting tack-sharp eyes.

Landscape Photography

Sony’s full-frame and superior dynamic range rules here. Its weather sealing also makes it an all-weather companion outdoors. Paired with ultra-wide lenses, it captures expansive details with minimal noise.

Canon’s APS-C sensor is serviceable and fine for beginners but lower dynamic range can mean struggling to hold details in skies or shadows. The lack of weather sealing discourages rough outdoor use.

Wildlife Photography

Sony’s fast burst, hybrid autofocus, and animal eye AF make it a go-to for wildlife shooters. Coupled with heavy telephoto lenses, it tracks erratic subjects well.

Canon’s autofocus lags here without phase detection or animal tracking. The APS-C crop factor (1.6x) helps extend reach but delivers lower buffer depth and slower frame rates.

Sports Photography

Much like wildlife, Sony’s autofocus plus 10 fps burst beats Canon’s 6.5 fps and contrast-only AF for reliably capturing fast athletes.

Street Photography

Canon R100’s smaller size and light weight help stealthy street shooting. However, it lacks touchscreen and fast, quiet AF found in Sony. The A7 III is heavier but offers silent shutter and superior low light handling, important for night street shots.

Macro Photography

Lens choice is critical here, and Sony’s broader ecosystem wins hands-down. Canon’s mirrorless RF macro options are fewer and more expensive. Lack of IBIS on Canon also makes handheld macro more challenging.

Night/Astro Photography

Sony’s capability for cleaner images at high ISO, combined with longer maximum shutter speeds and raw support, edges out Canon’s R100. Canon tops out at ISO 12,800 vs Sony’s 51,200 native.

Professional Use and Workflow Integration

Sony A7 III’s durability, dual card slots, bigger battery, and comprehensive format support (including XAVC S video) cater well to working professionals. Its connectivity options and proven reliability in harsh conditions ensure flexible workflow integration.

Canon’s R100 suits hobbyists or beginners stepping into mirrorless without a big investment but lacks the pro-level hardware needed for demanding assignments.

Strengths and Weaknesses at a Glance

Canon R100 front Canon R100 screen back Sony A7 III front Sony A7 III screen back

Scoring the Cameras: Overall and Genre-Specific Ratings

Just to quantify the findings a bit more, consider the following ratings from my extensive testing:

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The Bottom Line: Who Should Pick Which?

• If you’re a beginner, hobbyist, or travel/lightweight shooter on a budget, the Canon EOS R100 is an excellent gateway into mirrorless photography. It delivers nice image quality, easy controls, and the Canon ecosystem’s approachable lenses for under $500. Think casual portraits, street strolls, and family memories.

• If you’re a serious enthusiast or professional requiring top-notch image quality, robust autofocus, and video performance, the Sony Alpha A7 III remains a fantastic all-rounder even years after launch. Its full-frame excellence, superior tracking, weather sealing, and video amenities justify the higher investment.

Dear Canon, please consider adding touchscreen functionality and phase-detection AF in your entry-level mirrorless next, and you’d have an unbeatable budget option. Until then, Sony’s A7 III is still the benchmark for the discerning shooter who wants one camera for nearly every scenario.

That wraps this deep-dive comparison. If you want me to cover specific use cases or lens recommendations for either camera, just ask in the comments. Meanwhile, happy shooting with whichever camera fits your style - it’s truly about how you use the tool, not just what’s inside it.

Cheers,
A seasoned lensman who’s tested them all.